Medical information systems are commonly used by health care facilities for storing patient information, replacing, for example, paper-based flow sheets typically found at a patient bedside in most hospitals. An example of such a medical information system is the HP CareVue 9000 system available from Hewlett-Packard Company of Palo Alto, Calif.
While such systems provide highly satisfactory operation and have many advantages, a problem with current medical information systems is the speed with which a clinician may access patient data records in the system from a patient bedside. Typically, the clinician must scroll through a patient's data records in the database sequentially according to the date and time the data records were entered into the system. Where the patient has been in the hospital for a long time, review of these data records can be particularly slow. In contrast, with a paper-based chart, the clinician can simply flip through the pages of a chart. The restriction found in computerized medical information systems can be annoying to clinicians who desire much faster access to data records for a specific patient from a specific date and time.
Most tools which allow a user to access information in a computerized database are textually-based and thus require a user to enter accurately into the computer indices for the information to be retrieved. Often, these indices have special formats which need to be learned by each user. A user therefore takes more time to become familiar with such a system.
Non-textual tools for accessing information are not common in database systems. While graphical tools have been used in commercially-available word-processing, spreadsheet and graphics editing programs for navigating documents, on a line-by-line or page-by-page basis, these tools do not use the displayed data to assist in its navigation. Also, the relationship between a displayed document and any tool is fixed for all documents. For example, a vertical scroll bar in a word processor always relates to the length of the data file in a fixed manner.
The only use of a graphical navigational tool in a computer system using medical information, of which the inventors are aware at the time of filing this application, is found in the AIM product available from Hewlett-Packard Company, of Palo Alto, Calif.
The AIM product allows for receipt, storage and display of up to twenty-four hours of an arrhythmia waveform. The waveform data are stored in a linear array where each sample point is a fixed number of bytes. The time of the first sample point is stored. The time of the last sample point is determined by adding the number of samples, times the sample interval, to the start time. A bar at the bottom of the video display window representing the time between the first and last samples. By clicking on a point on the bar, the data for the corresponding time is shown by retrieving data from the corresponding location in the data file.